This invention relates to analytical devices and more particularly to devices for detecting the presence of at least one pollutant or other hazardous component in a gas sample. The invention further relates to a device having a plurality of individual electrical responses from a plurality of sensors with the responses forming a pattern characteristic of a hazardous component. More specifically, the invention relates to a portable instrument capable of being used in field locations for detecting and identifying at least one hazardous component in a gas by a comparison of the pattern of responses from the sensors with one or more standard patterns stored in a memory in the instrument.
Particularly with respect to use at field locations for chemical spills and the like, devices for detecting the presence of a pollutant or other hazardous component in a gas have generally been associated with a particular selected compound. Detection devices selective for hydrogen sulfide, carbon monoxide, ammonia, and the like may be considered as representative. Essentially, these devices measure one or a few selected pollutants and are not designed to identify the pollutant. When a gas for analysis may contain an unknown pollutant, it is usually necessary to obtain a sample of the gas and send it to a laboratory for a remote analysis. The time required for the transmittal of the sample and its analysis usually delays a meaningful identification of any harmful components and/or their concentration in the gas for a significant time.
Semi-portable versions of the more powerful laboratory gas chromatographic or infrared analyzers have been commercially introduced in recent years. Besides being rather heavy, bulky, unwieldy, and expensive, these instruments have certain inherent limitations. The gas chromatographic devices cannot operate in a continuous real-time monitoring mode. The infrared analyzers require a delicate optical system with a rather long absorption path, which contributes to their bulk, weight, and unwieldiness. These instruments must usually be operated and their results interpreted only by well-trained professionals.
One object of this invention is a device for detecting and identifying one or more hazardous components of a gas. A second object of this invention is a device capable of identifying a hazardous component in a gas from the response pattern of a plurality of sensors. A third object of the invention is a device for identifying any of a number of unknown hazardous components in a gas. Another object of the invention is a device capable of providing a varied pattern of responses and thereby capable of identifying a plurality of possible hazardous components in a gas. An additional object of the invention is a device capable of on-site analysis of a gas. A further object of the invention is a portable device capable of being easily transported to field locations and of being operated and used by unskilled or semi-skilled personnel. These and other objects will become apparent from the Detailed Description.